1. Field of the Invention
The present invention relates to a liquid crystal display device.
2. Description of the Related Art
In recent years, a liquid crystal display device is widely used as a thin and light-weight display device in personal computers or small TV receivers. Also, vigorous researches are being made in an attempt to use a liquid crystal display device as a large display element in wall-hanging type TV receivers or in electronic computers.
FIG. 1 shows the construction of a conventional color liquid crystal display device. As shown in the drawing, the conventional device comprises an array substrate 241 and a counter substrate 248 disposed to face the array substrate 241. A large number of pixel electrodes 245 and TFT's 242 are alternately formed on the array substrate 241. On the other hand, a large number of absorption type color filters 247 are formed on the counter substrate 248. Only one of the R (red), G (green) and B (blue) components of the light can be transmitted through each of these color filters 247 for display of a color image, with the other light components absorbed by the color filter. In other words, only 1/3 of the light can be utilized in each pixel, leading to a low light utilization efficiency. It should be noted in this connection that a long driving time of the display is required in, particularly, a portable computer, making it very important to improve the light utilization efficiency of the display. It should also be noted that, in the case of using an absorption type color filter, a large number of process steps are required for preparing each of R, G and B regions, leading to a high manufacturing cost of the display device.
When it comes to a projection type color liquid crystal display device, the light is decomposed into the R, G, B components by a dichroic mirror for improving the light utilization efficiency. In this case, three liquid crystal display devices are used for controlling independently the display of the three color components and, then, the three color components are combined again. In this case, required are three sets of a liquid crystal display device and an optical system, leading to a complex structure and a high manufacturing cost.